Hydrometer



F. R. WILSON Dec. 4, 1951 HYDROMETER 2 SHEETS-SHEET l Filed April 21, 1945 v INVENTOR. 4/z MK IZ. W/L so/V 'l mf Y @da 0l l 2 W F. R. WILSON Dec. 4 1951 HYDROMETER 2 SHEETS-SHEET 2 Filed April 21, 1945 snow Zenom-67 Patented Dec. V4, 17951 lUNI"1"]511) TST-ATYS* PATENT OFFICE nYnRoME'rER v Frank RfWilson, Lexington, Ky. Aptucafidnnpil 21, 1945,*serial` No. 589,485

1'1 Claims.

'"Tests made to determine the tree'zing'temperrature which V`the engine-'cidolling lids inautoymob-ile radiators lwill stand are usually Atriade :at any temperature that such fluids 4'may'happen 4to have at the time. It becomes necessary, 'f

therefore, to vcoriect the yordinary nlfiy'dr'orn'eter reading bya temperature factor. iMoreov'er, the various antifreeze materials employed 1 in reducing-the temperature datwhi'ch th'e uids in automobile radiators will-reeaevary as to characteri'stie's and results produeed.- Thus, even with mthe particular fanti'freeze lmaterial inl-the radiator known, the determination of the temperature rwhich "the cooling ii-uid Will vvWith'Sl'ja-Id feti-1l a vtedious and time consuming process yopen to lserious error.

Complicating 'such testing Aof the -coolin'ginud is the -factthat-frequerftlythe par- `Lticular antifreez'e material-in the radiator isfnot known, or la variety of antifreezematerials may have been introduced from'ltime totirne. Under such circumstances, the testing of the cooling "iiuid lby apparatus and methods heretofore knownA is doubly diiiicult and at `times v'prawz'tioally impossible.

.It is'an object of this invention, therefore-,fte providefainew 'and improved -hydrorneter by the fuse `of which the vfaults :of prior practices Jare overcome-'and th'e testin'gvof the fluids'lin automobilerradiators is made Jquick,easy 'andicetain Anotherobject of ttheyfinven"tion is to provide 'proved lhydron'ieter which automatically diierentiates'between heavier' than Water `and lighter than Waiterantiffreeze 1materials and, for either the heavier than water or lighter than water anti-Freeze materials, gives two readings obtainable "directly V'from the :float w'itfho'ut reference tolany `otner charts;Which'readingsiare corrected for the 'temperature of the viluid being tested.

Still'another object 'isto provide a lhydroineter adapted both'for the testing o'f-'therluids in automobile radiators, as YWell as testing `batteries, wi-'th ready, veasily Anuanipulajtec'l 'means ffor cor- 2 peratureof thefluid the radiator or the electrolyte in the battery.

'Not only has the determination of the freezing temperature which the fluid in the radiatorwill stand been a tedious and difiicult task in the fpast, but the amount of antifreeze material to be added Vto cause the fluids to withstand certain temperatures lhas veither been guess vwork Vor has required repeated testing after small additions of antifreeze material.

It is a further object 'of this invention, therevvfore, to incorporatein a hydrometer readily opervfable means for determining the V'quantity of anti- 'tr'eez'e material that needs to be added to the cooling Vfluid in 'an automobile Yradiator to conf'diltio-n it for withstanding a specc, low tem- "perature @therlobjects and' advantages will become apparenti-rom the following detailed description Vtaken in connection with the accompanying drawings, in which:

\Fig. 1 is an elevational View of a hydrometer 'embodyin'gmy invention in a simple, preferred form.

Fig.. 2 'is a longitudinal laxial section through the :device of Fig. 1.

".Fig. 3 is -a section on line 3--3 'of Fig. 2.

Fig. 4 lis 'a perspective view Vof a sleeve surrounding .an'd rotatable on the barrel of the hydrometer, but on a smaller scale than Figs. Al'to Fig. f5 is a .perspective view of a sleeve or shell, Vfon'the f'same scale 4as Fig. 4, that surrounds the other sleeve 'and is "fixed to the barrel ofthe device.

Figs. i6 :and '7 are views .similar to Figs. .1 and '2, illustrating 'a modification.

K'Fig. 8 is a section on line t-- .of Fig. 7.

Fig. 'Qis-a section "on line S-S of Fig. '7.

Fig. `1'0 is a section, -on a larger Vscale than Fig. 56, -on line lll---I d -offthat figure.

Fig. -1-1 -is a perspective View, on la smaller iscale than Fig. 7, -:showing an inner, rotatable sleeve. y

Fig.`12 isa perspective view, on the same scale asiFig. 11, olf 'thestationary outersleeve 'in Figs. V"6 and?, the vrcalculator being omitted.

Referringrst to the form of the invention shown in rags. -1 to 5 of the drawings, the hydviomete'r comprises generally -a glass tube o1- *barrel which carries at its ylower end `a more for less :conventional tip or nozzle 2 made of yrubber for' rubber-like composition through luid to yloe testedisf'dr'avvn into and 'discharged "from theiglass tube. At its upper-end, the tube I carries the usual rubber bulb 3. Within the tube or barrel I is a iloat 4 having the conventional, enlarged bulb 5 at its lower end and an elongated, upwardly extending stem E. The iloat, as is conventional, is free to move longitudinally of the tube in response to the level of and the buoyancy of the liquid drawn into the tube, and is centered with respect to the tube and held coaxial therewith in conventional manner.

In this form of the invention, the hydrometer is so constructed as to constitute what for convenience will be termed a float reading hydrometer, that is, a construction in which 'the temperature values that the solution tested will stand are read directly from the float, more particularly, in this instance, from the top of the float which may be formed to constitute a pointer l. In order, therefore, thaty the level of the float may vary only with the specific gravity of the fluid being tested, and not also in accordance with the quantity of the fluid drawn into the barrel of the hydrometer, means is provided for readily obtaining a constant level of the fluid drawn into the barrel of the hydrometer. Herein this means takes the form of a chamber 8 closed at its upper end and open at its lower end, and formed by means of a partition having a portion 9 extending as a chord across the tube I and a portion I serving as a closure for the top of the chamber 8. It is believed readily apparent that the lower edge of the pargition will determine the height to which the liquid will rise in all except that small passage Il in the tube I which extends parallel with the chamber 3 and opens to the rubber bulb 3. As the liquid drawn into the tube rises to the botlom of the partition, the chamber 8 will be sealed by the liquid and hence there will be no further exhaustion of air from this chamber and no further rising of the liquid in the chamber, and thus there will be formed for all practical purposes a constant liquid level. The stem 5 of the float 5 will, of course, under proper conditions, pierce this level and pass into the chamber 8 so that, regardless of variation of .f

the height of the column of liquid in the passage I I, the liquid having a buoyant eiect on the float will always have the same level in the tube I when the hydrometer is properly operated.

With this construction, the level of the float will always be an indication of the specic gravity of the fluid being tested and the float and particularly some portion thereof may be employed as a pointer or indicator, and there is no longer any need to have the float itself contain some calibrated chart from which a reading indicative of the specic gravity of the fluid tested can be obtained. This factor is herein utilized to make possible a hydrometer which, in the first place, will give a reading, corrected as to temperature of the fluid tested, directly from the iioat, and in the second place a hydrometer which will enable a variety of antifreeze solutions to be tested and which will give a safe reading even when the particular antifreeze material in the liquid being tested is not known. To that end, there is rotatably mounted on the tube or barrel I a cylindrical sleevey generally designated I2. lIhe sleeve I2 is usually larger in diameter than the tube I, the exact dimensions being determined by factors later to be made known, and is of a length to extend from the tip or nozzle 2 to a point somewhat short of the top of the tube I. The sleeve has end walls I3 and I4 each formed with a central aperture I5 just slightly larger 4 than the tube I and with the lower end of the sleeve formed with a radially outwardly projecting and knurled ange or bead IE. The sleeve I2 is rotatably supported in position by the tip or nozzle 2 of the hydrometer on which the lower end wall I4 of the sleeve I2 rests.

Over about two-thirds of the upper end the sleeve is formed with a plurality of longitudinal slots I'I uniformly spaced circumferentially of the sleeve. Each of the slots is just sufliciently wide to permit the head or pointer 'I on the upper end of the float to be viewed therethrough. Herein ten slots I'I are provided, though this number may be varied depending upon the lineness of the temperature factor adjustment to be I made. Immediately adjacent each slot, the sleeve `a solution being tesled will freeze.

I2 carries four scales I8, i9, 2@ and 2l composed of numerals indicating the temperature at which The scales, therefore, run from 32"" F., the freezing temperature of water, to progressively lower temperatures in both directions away from the symbol W, dividing the scales and representing the position which the top of the iloat will assume when a solution composed only of water is being tested. Certain antifreeze materials have a specic gravity higher than water and hence solutions composed of such materials and water will cause the float to assume higher and higher positions as the percentage of antifreeze material is increased, and hence the scales I8 and I9 indicate lower and lower freezing temperatures as one progresses up the scale from the symbol W. Conversely, where antifreeze materials having a specific gravity lighter than water are added, the float will take a lower and lower position as the percentage of antifreeze material increases, and hence the scales 20 and 2I indicate lower and lower freezing temperatures as one progresses downwardly from the symbol W. In the actual hydrometers, below zero readings of the scales will, of course, be indicated in some suitable, easily distinguishable manner, such as by the employment of red numerals. Herein minus signs have been placed at the ends of each of the vertical columns composed of the scales I8, 20 and I9, 2l to indicate that each of the four scales progresses from the letter W to successively lower temperature readings including below zero readings.

It is believed apparent from the foregoing that with the construction shown the hydrometer will automatically differentiate between lighter than water and heavier than water antifreeze material, so that it is not necessary for the individual testing the coolant fluid in a radiator to know whether the antifreeze material in the fluid is heavier than water or lighter than water. If desired, the scales may be calibrated for particular and well known antifreeze materials. For example, scale I 8 may indicate the freezing temperatures that a solution containing the material known by the trade name Prestone will stand. The scale I9 could give the same indication for the material known by the trade name Zerex, and scales 20 and 2l could give the readings for alcohol and methanol, respectively. Preferably, however, the scales do not indicate the freezing temperatures of solutions having any particular antifreeze material therein, but scales I8 and 2D are so calibrated as to indicate the temperatures which yantifreeze materials giving the more protection will stand, whereas, the scales I9 and 2l are calibrated to indicate the temperatures which the commonly known antifreeze materials giving the lesser proniemeer;

ftection 4will stand. With this arrangement, fthe `scales t9 landrZI willalwaysfgive a Lsafe"fread- 'ing which the operator rkof the lvehiclecan"Irely upon even though he is not aware ofthe particular -antifreeze material-in the radiator fof his car.

vThe scales I8vto52v0,1inclusive,loff'course; are the rea-'dings ycorrected 'to a.'particular Y'ternpe'ratiire of the solutionbeing tested. llila'clfrfof *thefslots vril, of course, 'has four such scales viassociat'ed therewith with each slot-,and the scales associated therewith representing a different 'temperature of the solution being tested andwith 'thescales properly calibrated' to indicate tl'liecorrect Vlreezing 'temperature rwhicn #the r solution *willf'stand .Means is provided herein for quickly and linfalliblyindicating to `the operator which "of lthe :slots I1 and the scales `:associatedltl'rerewith is a plurality of windowsextending.'progressivelyV circuniferentially of the #sleeve 'and Aeach being at a diierent level. The steps correspond in number to the number of vslots I1 and each fstep .is bisected by a longitudinal extension 'of .the vcenter vline of the slot. Mounted in 'the tip lor nozzle 2 isa thermometer 23 adapted for cooperation with the'steps22. The thermometer is generally Lshaped, having its bulb 24 disposed in the passage leading to the tube`1 iso as to lbe subjected to the temperature 'of the `solution being tested. From the .bulb 2'4 a `short or base leg extends radially outwardly kwith the main or indicating portion 26 extending vertically upwardly to lie just within the sleeve I2. The thermometer and the sleeve I-2 v'are so fcoordinated that when the sleeve is rotated to bring one of the .steps 22 approximately to the vlevel of rthe top of' the lcolumn of temperature responsive iiuid in the thermometer, the proper slot vII with Aits associated scales will be presented tothe view of the operator of the :hydrometer- The hydrometer is completed by a cylindrical housing 2'! slightly .largerthan the sleeve I2 so as to be receivable over the .sleeve and act as a protection therefor and `also to mask .all but one of the slots I'I and its associated scales. v'Ihe -housing 21 is open at its lower 'end but at its upper .end is formed with an annular vwall 2B and va split collar 29 by means of which the housing may be rigidly secured vin a .-xed position ion the tube I. 'Formed inthe housing is an elongated slot 3i) extending substantially from end to end of the housing lso as to Vexpose therethrough a portion of the entire sleeve I2 and the Vthermometer and ii'oat behind the fsleeve. In 'width the slot 3i! is made just wide enough r5to expose one set of scales 'when the corresponding .slot -II is centeredin the slot 30.

The advantages and, particularly, the ease with which fluid may be .tested become quicklyzapparent when the operation of the hydrometer -is considered. The operation will, therefore, .be described brieily. With .a ihydro'meter con- 'structed in accordance with this invention, afga- .rage or gasolinegstation 'attendant Ycan*readily i6 land' fqui'ckly advise the :operator 'of ian vautomobile `:of the 'freezing temperature' the :solution in Ahis lradiator will stand. To determine this .temp-erature, the 'operator `.draws into the hydrometerfa sufficient nquantity of thelsolution or coolant' duid `to yiill fthe tube at .least upto the level of the lower lend fof the 4partition .9. Theattendant 'need not spend any 'time in accurately adjusting the quantity of the :fluid drawn AintoV the ihydrometer 'for a 'constant level fof `fluid effectiveto lact on the iloat of the hydrometer yautorziatically ass'ured by -the constructionof the -hydrometen Next 'the V'atteifidant simply rotates 'the sleeve I2 'untilso'me foneo the Vstep/S22 is adjacent ori-'approximately adjacent ltlfie top of ythefcolumn of temperature responsive fiiud vinthe thermometer. With the .main portionof 'the ythermometer `irn- 4m'e'diately behind the sleeve, this V"adjustmentTis readily and accurately made'w'ith'out possibility `of error 4due 'to thelangle'for 4other factors at which .the stepandth'e column of 'liuid and the thermometer are sighted. With the 'rotation of `the sleeve to bring a step 22 to the position above described, the proper slot I'I -is brought into View through the slot Si) in 'the housing 2. The attendant then simply 'notes the figures opposite the` top or pointer? of the float. It is no'tnec-essary that the operator know "beoreha-nd whether the "antifreeze material' in the 'coolant fflu'id 'is A'of the -'heavier or Lthe lighter `than waterftype, for the hydrometer .as ,here constructed will 'give the correct reading `for either. If vthe -car owner knows 'the particular antfreeze Imaterial which he has in the ycar "radiator, the attendant will iknow whether it is one of the'better grades or one ofthe poorer lg'rade's-offantfreeze materials.

'1f it is one 'o'f 'the better grades, the attendant will :advise the car Vownerthat the solution vwill `stand a temperature as indicated by the scale f8 or 2li, depending -upon where the pointer of the oat is positioned. If 'it "is one of 'the poorer grades, the attendant will take a iigure from' the vscales 'i9 or 2i. Should the car owner be completely ignorant of the'brand Aof antifreeze material in .his radiatonor ushould vhe advise the `attendant that a variety of brands have from time to time been added, "the attendant can by -taking a"figure .from-scales `Iii or'I advise the car owner -of a safe temperature which his radiator fluid will withstand.

Thus it will be seen that the hydrometer herein disclosed obviates all necessity of 'taking Ia reading by the hydrometer, thentaking a temperature read-ing, and then goingto a chart and tracing `one column horizontally across the chart and another column 'vertically offthe'chart to find the point of intersection, which will give the temperature which the solution' will withstand, assuming, of course, that the antifreeze material in the solution is definitely known, with the attendant great possibility of `error in making these several readings, interpolation's, etc. Further, it provides at a 'glance a safe temperatur-e when the Vantifreene material Vin the solution tested is unknown. .Without this hydrometer, such a safe temperature -could be ascertained only by making the above laborious determination 'for each known antifreeze 'material' andthen taking the highest of the readings thus ascertained.

Referring now to the form of the invention shown in Figs. 6 to 12 of the drawings, the hydrometer comprises generally -a glass vtube or barrel .35 which carries at its lower end 'a more Vor less lconventional 'tipor nozzle 3'6 made -of rubber lor .rubber-likecomposition through lwhich ilui'd to be tested is drawn into and dlscharged'lrom the glass tube. At its upper end the tube 35 carries the usual rubber bulb 31. Within the tube or barrel 35 is a iioat 38 having the conventional, enlarged bulb 39 Vat its lower end and an elongated, upwardly extending stem 40. The float, as is conventional, is free to move longitudinally of the tube in response to the level of and the buoyancy of the liquid drawn into the tube, and is centered with respect to the tube and held coaxial therewith in conventional manner.

In this form of the invention, the hydrometer is so constructed as to constitute what for convenience will be termed a thermometer reading hydrometer, that is, a construction in which the temperature values that the solution tested will stand are read directly from the column of temperature responsive Huid of a thermometer which is subjected to the solution being tested. This form of the invention, moreover, is adapted also `to test wet cell batteries and, additionally, includes means for readily calculating the amount of antifreeze material that must be added to a car radiator of given capacity in order that the resultant solution be capable of withstanding a specific freezing temperature.

To the above ends, the hydrometer is so constructed that the level of the float 38 will vary only with the specific gravity of the fluid being tested and not also in accordance with the quantity of fluid drawn into the barrel of the hydrometer. Means is provided for readily obtaining herein a constant level of uid drawn into the hydrometer and effective to act on the float. Herein this means takes the form of a chamber 4| closed at its upper end and open at its lower end, and formed by means of a partition having a portion 42 extending as a chord across the tube 35, and portion 43 serving as a closure for the top of the chamber 4|. It is ybelieved readily apparent that the lower edge of the partition will determine the height to which the liquid will rise in all except that small passage 44 of the tube 35 which extends parallel with the chamber 4| and opens to the rubber bulb 31. As the liquid drawn into the tube rises to the bottom of the partition, the chamber 4| will be sealed by the liquid and hence there will be no further exhaustion of air from this chamber and no further rising of the liquid in the chamber, and thus there will be formed for all practical purposes a constant liquid level. The stem 4U of the float will, of course, under certain conditions, pierce this level and pass into the chamber 4| so that, regardless of variation of the height of the column of liquid in the passage 44, the liquid having a buoyant effect on the float will always have the same level when the hydrometer is properly operated.

With this construction, the level of the float will always be an indication of the specific gravity of the fluid being tested, and the float, and particularly some portion thereof, may be employed as a pointer or indicator and there is no longer any need to have the float itself contain some calibrated chart from which a reading indicative of the specific gravity of the fluid tested can be obtained. This factor is herein utilized to make possible a hydrometer adaptable both for testing coolant fluids in radiators and for testing wet cell batteries with the hydrometer for both types of tests giving an indication corrected by a temperature factor. To that end, the tube 35 proper carries a rst scale 45 herein composed of letters, `though it is to be understood any and the sleeve'56 is a thermometer 6|.

r8 other type of symbol might be employed. Above the scale 45 the tube 35 carries a second scale 46 bearing numerals indicative of the charge on a battery.

Nonrotatably mounted on the lower end of the tube so as not to interfere with any portion of the scale is a cylindrical housing 41. This housing has a bottom Wall 49 having an eccentrically positioned aperture 5D large enough to receive the tube 35 therein. The aperture 50 is eccentrically located in order to bring a particular portion of the housing as close to the tube 35 as possible, and the housing 41 is supported in fixed position on the tube by having the bottom wall 49 clamped between an annular shoulder 5| and a nut 52 forming a part of the nozzle or tip 36. The portion of the housing immediately adjacent the tube 35 is formed with a rectangular opening 53 disposed vertically and spaced upwardly a short distance from the bottom of the housing 41. Immediately below the opening 53 is a small, square opening 54, and beneath the opening 54 the housing is formed With an elongated, horizontally extending slot 55 and the housing is, moreover, depressed inwardly for a purpose that will presently be made known.

Rotatably mounted within the housing 41 and encircling the tube 35 is a cylindrical sleeve 56 just slightly smaller in diameter than the housing 41. At its lower end the sleeve 56 is formed with a knurled, radially outwardly extending bead or rib 551. This bead is very slightly smaller than the internal diameter of the housing 41 and thus acts as a guide retaining the sleeve in concentric relation to the housing and, of course,

projects slightly through the slot 55 of the housing to adopt the sleeve for rotation by manipulation from the outside of the housing. Immediately adjacent the bead 51 the sleeve 56 carries a plurality of symbols, herein letters, corresponding to the symbols of the scale 45. These symbols are uniformly spaced around the sleeve and are visible through the square opening 54 in the housing 41. vertically above each such symbol on the sleeve there is formed in the sleeve an elongated slot 58. Adjacent to and associated with each such slot 51 are two columns of figures 59 and 69 representing Fahrenheit temperatures at which the solution being tested will freeze. The slots `58 can be and are very narrow, and theopening 53 in the housing 41 has a lwidth and length such that when one of the symbols on the lower end of the sleeve is centered in the opening 54 one of the slots 58 and its associated columns of figures 59 and 6l) will be visible.

Mounted immediatedly behind the opening 53 This thermometer is preferably mounted externally of the tube 35 so as not to interfere with the float-38, but may also be mounted internally of the tube. The only essential is that the bulb of the thermometer be positioned in the tube or vthe tip 33 so as to be subjected to the uid being tested. It will be seen from the foregoing that, when the sleeve 5t is rotated to any position in which one of the symbols carried by the sleeve is centered in the opening 54, there will be visible through the opening 53 not only one of the slots 58 and is associated columns 59 and 3|), but also visible through the slot will be the column of temperature responsive fluid in the thermometer. The columns or scales 59 and 60 are so correlated with respect to the symbols on the scale 45 thatthe gure opposite the top of the temperatureresponsive. fluid in the, thermometer gives a reading of the freezingftemperature which the solution will stand corrected to take into account the temperature at which the fluid was tested.

It is to be noted that the scale 45 is composed of two portions divided by the word watern The upper portion will, of course, represent the readings utilized when a solution containng a heavier than water antifreeze material is being tested, while the lower portion will be utilized when solutions containing lighter than water antifreeze material are being tesled. It is not necessary, however, that the garageor filling station attendant know whether the coolant fluid contains heavier or lighter than water antifreeze material, for that will automatically be indicatedby the hydrometer. The columns or. scale` 59 and 6B can be calibrated to give readings for particular, commonly employed antifreeze materials, such as alcohol, methanol or the materials known by the trade names of Prestone. or Zerex. Preferably, however;v the-column u is so graduated as to give the temperatures thatv antifreeze. materials. giving the morel protection will withstand, While column 5.9 is so calibrated as to give the temperatures. which antifreeze material giving the lesser protection willv withstand.. Wheny so, calibrated,A an` attendant can always. readily give to the owner oi the car whose coolant uidis being tested a figure whichA is a safe gure regardless of whether the.V particular antifreeze material in the coolant luidis known or not.

The employment. ofthe. hydrometer constructed as. herein described, isextremely simple. All the attendant` need do is to draw into the barrel 35 of the hydrometer a quantity of uid,such that there is some rise of the fluidi-n the. passage dit, thereby assuring that there is suincient. fluid drawnl into the tube to enable the. constant level feature of the tube tocome intooperation- The attendant then notes the symbol of the scale 45 opposite which the top of. the float 38 kcornes to rest. The attendant then rotates. the sleeve 55 until that particular symbolappears in the opening 54. The freezing temperature which the solution tested will withstand is readily obtained simply by noting the location of the top of the column of' temperature responsive fluid oi the theimometer. If the nature of the antifreeze material in the coolant is known and, moreover, is known to be one of the better grades, the attendant reads the gure in the column Si! which is opposite the top of the column of the temperature responsive fluid in the thermometer. If the antiireeze inaterial is known to be one of the poorer grades, or if the material isV unknown, then the corresponding figure from column 59 is utilized which, as above stated, will always give a safe reading; It is to be appreciated that the number of slots 5 8 and hence the number oi charts aSSociated therewith can be varied;l depending upon the degree of fineness which the temperature of the solution being tested-will withstand is to be determined. Further, it is to be appreciatedY that, while the housing and the sleeve have herein been described as having openings or slots, the same effect can, or course, be obtained by the employmentA of transparent material for the areas, since sight through thehousing andthe sleeve are the essential requirements and* wheth- 'erxor notmaterialis presentV or isnot present 1S; of course, whollyl immaterial;

rIrestingv of a battery is eiected in Ysubstantially thesame manner asA the testing of* the coolant in a radiator.` The electrolyte ofthe battery is drawn into the barrel of the hydroi-neter. The sleeve 56y is then rotated to bring` into registry with the opening 53` a particular slot, herein designated by the` symbol BA, which has associ,- ated with it a scale-particularly designed for'use in determining the charge on a. battery being; tested. After this scale has been brought into registry with the opening 53., the-attendant notes the numeral which is opposite the top of the column of temperature responsive fluid in the thermorneter. Ify this gure is above the zero in the column oflgures, the gure is added to that particular one of the-figures in the scale d opposite which the top of" the oat 38' has comel to rest. Ifl the top of the column of temperature responsive iluid of the-thermometer is opposite one.- of the numerals below the zero in that column, that numeral is subtractedfrom the reading indicated by the top of the iioat, The resultant: number then gives the charge on the battery corrected to take into, consideration the temperatureoi the electrolyte being tested.

In order that the amount of antifreeze ma.- terial necessary to be. added to aradiator in order that the resultant solution will be able to withstand; a specic freezing temperature may be taken out of the realm of pure guess worker. a trialand error procedure, means is incorporated inr this hydrometer wherebyfthe quantity-*orantifreeze material to be added may readily audaccurately be determined. To that end;A there, is nonrotatably mounted on the housing 4-1 above the opening 53 a chart 64 containingV numbers representingquarts of antiireeze material, with the numbers arranged-in groups and in'horizontal and vertical columns. Hereineach group iscomposed of nine figures, arranged in three horizontal and threev vertical columns, with the horizontal columns representing divisions of radiator capacity, and with the vertical columns representing brands or grades of antifreeze material. It wi-ll be readily appreciated, of course, that these groups could be arranged to contain a lesser` or a greater number of' numerals', again depending upon the degree of precision desired in determining the result sought. Rotatably mounted'ion the housing externally thereof is a ring 'adapted to be supported against downward movement by a bead (it` formed in the housing 41. The ring 65- has a widened portion 61 having an aperture 68 formed therein which is just large enough to encompass onegroup of the numerals of chart 64. To one'side of the opening 88 the widened portion 6,1 may carry numbers indicating the capacity in quarts of a car radiator, and beneath the openingl 68.- may be symbols representing three common brands or grades of antiireeze material.

YThe widened portion @l is at its top edge and housing. 41. 'ro hold therme in againstioss orf Y ofgthe, topvv of the,y housinga disk 13 secured to thetube by acollar 'ht andextending radially outwardly to overlie the ring 'lyispreierazbly provided. This disk at the same time forms a closure for the top of the housing 41.

To use the calculator just described, the garage attendant rst tests the coolant in the radiator, especially if it is known or suspected that it already contains some antifreeze material. After it has been determined what temperature the coolant will withstand as then constituted, the attendant rotates the ring l0 so as to bring opposite an arrow 'l5 on the chart 64 that numeral of the scale ll which is closest to the temperature just determined. For example, let it be assumed that the coolant will withstand a temperature of 20 F. The car owner is then asked for what temperature he wishes to fortify his coolant in the radiator. Let it be assumed, for example, that the car owner wishes to condition his car to withstand 0 F. The attendant then rotates the ring 65 to bring the pointer 69 opposite zero on the scale 1l. As a result, there will be framed in the opening 68 gures indicating the number of quarts of various types of antifreeze material that must be added, depending upon the capacity of the radiator of the particular car, in order to condition the car to withstand zero temperatures. Again, by way of example, if the car has a radiator capacity of from twelve to fteen quarts and the car owner wishes to employ an antifreeze material of the type of grade B, it will readily be seen that seven quarts of antifreeze material will K have to be added.

It is believed that in the foregoing hydrometer there has been provided an instrument which, because of its utility to perform a variety of testing operations, will be unusually convenient and hence a great time saver. It also will save a great deal of time even in the testing of antifreeze solutions alone and, vabove all, will enable a determination to be made which at the present time cannot be made without very tedious and complicated efforts and thus usually is not made. Further, this hydrometer makes it possible for an attendant, while he is testing the coolant in a radiator, to advise the car owner quickly and accurately of the amount of antifreeze material that must be added in order for the coolant to be able to withstand a certain freezing temperature,

I claim as my invention:

l. A hydrometer device comprising a container .-A

for liquid provided with a compartment having an open lower end spaced a substantial distance above the bottom of the container, whereby air will be trapped in the compartment when the liquid rises above the lower end of the compartment, a float element in the container having a portion in position to rise within the compart- 4ment when liquid enters the container, a thermometer on the container to indicate the temperature of the liquid in the container, a member movable relatively to the container and hav- `ing thereon a plurality of vertical scales diiering from each other and each calibrated to give ,readings of the levels to which the oat element compartment, a long inner sleeve surrounding and rotatable on the container and having long, longitudinal slots spaced apart circumferentially of the sleeve, there being atleast one scale along each slot to provide readings for different levels which the float element may reach, a stationary outer sleeve surrounding the inner sleeve and having therein a long window sufficiently wide to expose any one of said slots and the corresponding scale or scales when the slot is properly registered within the window, a thermometer for indicating the temperature of liquid in the container, the thermometer and the float element being so located that both are visible through said window when a slot and window register, and a visual gradient on said inner sleeve cooperating with the indexing element of the thermometer to select the particular slot which is to be exposed.

3. A hydrometer for testing the coolant in automobile radiators to determine the freezing temperature which the coolant will withstand comprising a container for lthe coolant to be tested including an elongated tube, means forming within the tube and at the upper end thereof when the hydrometer is held in vertical posi tion a downwardly opening chamber operable to limit the rise of coolant within the chamber as the coolant to be tested is drawn into the container to provide a constant level of eifective coolant, a oat in the container having a stem portion operable to project into the downwardly opening chamber when coolant is drawn into the container, a thermometer associated with the container to be responsive to the temperature of the coolant drawn into the container and having a main portion extending parallel with the cylinder, and a sleeve rotatably mounted on the container, said sleeve being partly opaque and partly translucent and having at the portion opposite the thermometer a plurality of visual steps spaced longitudinally of the sleeve so that some one of the steps is adapted to be brought by rotation of the sleeve into approximate registry with the top of the column of temperature responsive iluid in the thermometer, said sleeve having a plurality of narrow, longitudinally extending windows in its upper portion, each window being associated one with each of said steps, and said sleeve having a scale associated with each of the windows indicating directly by noting the numeral on the scale opposite which the top of the oat/ comes to rest the temperature which the coolant being tested will withstand, at least the portion of the tube opposite the window in the upper portion of the sleeve being transparent to permit the top of the float to be viewed therethrough.

4. A hydrometer for testing the coolant in au-l tomobile radiators to determine the freezing temperature which the coolant will withstand comprising a container for the coolant to be tested including an elongated tube, means forming within the tube and at the upper end .thereof when the hydrometer is held in vertical position a downwardly opening chamber operable to limit the rise of coolant within the chamber as the coolant to be tested is drawn into the container to provide a constant level of eiective coolant, a float in the container having a stem portion operable to project into the downward-- ly opening chamber 'when coolant is drawn into. the container, a thermometer associated with the container to be responsive to the tempera- #use Qf the coolant drawn into the container and f 13 having'a main'portion extendingparallelwith the container, and ya sleeve rotatablymountedV on the container,` said sleeve'beingpartly opaque and partly transparent and having at ther-portion opposite the thermometer a plurality of visual steps spaced longitudinally of the sleeve so that some one of the steps is adapted to be brought b-y rotation of the sleeve into approximate registry with the top of the columnV ofY the temperatureresponsive iiuid in the thermometer, said sleeve having a plurality of narrow, longitudinally extending windows in its upper portion, each window being associatedV oneV with each ofsaid steps, and said sleeve having four scales assoelated with each window and composedgof'numerals indicating temperatures, thev scales extendingv along the windowv on oppositev sides thereof with the upper two being utilized when liquids, having a density greater than water are being tested, and the lower twol being utilized when liquids having a density less than water are. being tested and with the scales .on one side of the Window indicating optimum conditions and the scales, on the other side ofthe window indicating minimum conditions,k the tube being transparent to permit observation of the iioat through a vwindow andthe tube to` obtain directlyby notingY the numeral opposite the top of the float. thetemperature which the coolant being tested will withstand. o

5. Ahydrometer device, including a. cylindrical barrel, calibrated to, indicatel relative specic gravity of a series o f, liquids. of .different densities, by means of arbitrary characters, an inner sleeve surroundingV and rotatable on the, lower part of the barrely and having as-many longitudinal slots spaced apart circumierentially of the sleeve as there. are said arbitrary characters, there being a scalealong each slot, each., representing temperatures below which one of' said different liquids may freeze, a stationary outer sleeve surrounding the inner sleeve andhaving therein a window sufficiently longY and wide to expose one of the slots and its accompanying scale when that slot is properly registered with the window, a thermometer indicating the temperature of 'liquid in the barrel, the thermometer being so located thatl it is visible through the window and the slot registering with the window, whereby the: temperature indicating element-of the thermometer serves as afpointer cooperating with the; Scale-,beside the slot through which the thermometer is being viewed.

6.4 A` hydrometer comprising; an elongated tube, a-y float in said, tube, means formed within the tube for buoying4 the float by a constant level of liquid when a minimum amount of liquid is drawn into said tube whereby the position of the oat will be determined by the density of the liquid only, a pair oi scales carried by said tube one utilized in the testing of radiator coolant fluid containing antifreeze material and the other in testing wet cell batteries, a thermometer associated with said tube to be disposed to the fluid therein having a main portion extending longitudinally of said tube, a sleeve rotatably mounted on said tube opposite the longitudinally extending portion of said thermometer and having a plurality of Windows formed therein extending longitudinally of the sleeve through which said thermometer is visible when the sleeve is rotated to bring a window into registry with said thermometer, at least one scale composed of numbers c indicating temperatures at which a liquid tested 14 al symbol on. the sleeveassociated .with cachot' the' windows:r corresponding tothe symbols ofthe scale on said tube employed for testing liquids containing antifreeze. material, wherebyl the temperature at which a. solution containingA antii'reeze material may be obtained by notingthe number on the sleeve` opposite the-top oi the column of the temperature responsive fluid in the thermometer after the sleeve Vhas first been rotated to bring into registry with the thermometer that window corresponding to the symbol on said tube opposite the top of said iioat, and a single one of said windows utilizable to effect temperature A corrections when the hydrometer is being employed tol test'awet cell battery.

7J. In a hydrometer, a tube for receiving fluid tobe tested, a float in saidtube, a thermometer responsive to-the temperature of the fluid drawn into said tube having a portion extending longitudinally ofsa-id tube, cylindrical housing fixedl'y` secured in-surrounding relation to said tube hav-ing a bottom wall, a sleeve rotatably mounted within saidfhousing resting on the bottom. Wall of said housing, an annular chart'fixedly carried on said housing', anrst annular-member rotatably mountedy in surrounding relation toA said housing, saidhousinghaving an outwardly extending bead forming a support for said member, a second annular member rotatably mounted on said housing having'a portion disposed exe ternally-of said housing anda portion internally of said housing, the portion internally of said housing servingto overliethe upper end of said sleeve: and retain .the same against longitudinal movement relative to said housing, saidfchart and said annular members cooperating to form a calculator for determining the quantity of antifreeze material tobe added to the radiator of an automobile to fortify the coolant in the radiator .to withstand a particular freezing temperature, and a disk-like member fixedly secured to saidv tube-and extending radially outwardly to overlie said-second annular member to hold the same against loss off of the upperendV of' saidhousing.

8. A combined tester and calculator for use in conditioninggthe coolant-in'` automobile radiators to withstandcertain freezing temperatures comprising, in combination, a hydrometer indicating -directly thereonthetemperature which a fluid being tested will withstand including a cylindrical housing, andmeans' carried by said housing operable for calculating; the amount of antifreeze material necessity to, be added to fortify the coolant in an automobile radiator against a particularffreezing, temperature comprising, anannularY chart composed'of groups of numerals divided into horizontalrows in accordance with ranges of automobile radiator capacities and into vertical rows representing antifreeze materials of different makes or characteristics, a rst annular member rotatably mounted on said housing adjacent said chart and bearing indicia representing temperature values above and below 0 F. having a spacing corresponding to the spacing of the groups of iigures of said chart, and a second annular member rotatably mounted on said housing having an enlarged portion With a Window therein of a size to frame one of said groups of numbers of said chart, the enlarged portion of said second annular member bearing at one side of the window indicia ining different makes or grades of antifreeze material.

9. A hydrometer device comprising a cylindrical, transparent container for liquid, a float element in the container, the container having a downwardly opening compartment above said element to trap air within the same when liquid in the container rises above the lower end of the compartment, a long inner sleeve surrounding and rotatable on the container and having long, longitudinal slots spaced apart circumferentially of the sleeve, there being at least one scale along each slot to provide readings for different levels which the iioat element may reach, a stationary outer sleeve surrounding the inner sleeve and having therein a long window sufficiently wide to expose any one of said slots and the corresponding scale or scales when the slot is properly registered with the window, a thermometer for indicating the temperature of liquid in the container, the thermometer and the noat element being so located that both are visible through said window when a slot and window register, and said inner sleeve having visual steps thereon cooperating with the indexing element of the thermometer to select the particular slot which is to be exposed.

10. A hydrometer for testing' solutions having antifreeze material therein comprising a container for the solution to be tested including an elongated barrel of transparent material, a bulb xed to one end of said barrel for expelling uid from or drawing fluid into said container, means within the barel forming a chamber extending longitudinally of the barrel, the chamber being closed at the top and open at the bottom to form a trap for air preventing liquid from rising in the chamber when the barrel is iilled above the bottom of the chamber, iirst indicating means comprising a float in said container, said float having a stem portion operable to enter the chamber, second indicating means comprising a thermometer extending longitudinally of said container and mounted to be responsive to the temperature of the liquid drawn into said container, and means for obtaining readings, corrected as to the temperature of the solution to be tested, indicating the freezing temperature of the solution by employing a reading obtained from noting the position of the upper end of said iloat, such last mentioned means comprising a member rotatably mounted on said container, said member having a plurality of longitudinally extending, circumferentially spaced, narrow sight openings disposed to have at least one of said indicating means visible therethrough and having a column of gures adjacent each opening for giving a reading of the freezing temperature which the' solution will withstand, a casing for containing said rotatable member, said casing being non rotatably mounted on said container and having a longitudinally extending sight opening through which one of the first mentioned sight openings and an associated column of figures of said roe tatable member are visible, and said rotatable member having markings adapted to be brought into registration with the thermometer reading.

11. The hydrometer of claim 10 having therein means to determine the quantity of an antifreeze material that must be added to guard against freezing of an engine cooling solution at a given temperature lower than that indicated by a preliminary hydrometer reading, which comprises three long members arranged side by side, the rst or central member being stationary and the other two being movable lengthwise of the iirst member, a row of numbers on and distributed lengthwise of the second member indicating temperatures from a point well above to a point well below 0 F groups of numbers representing quarts distributed along the central member, the central member bearing a mark with which any number of the second member may be registered, a mark on the third member adapted to be caused to register with any number on the second member; and means on said third member to select one of the groups of numbers on the central member and a particular number in that group and indicating the number of quarts of antifreeze needed, depend ing on which of a plurality of types of antiireeze is under consideration and on the capacity of the cooling system, when the iirst-mentioned mark registers with the number corresponding to the hydrometer reading for the solution and the other mark registers with the number corresponding to the hydrometer reading desired for the solution.

FRANK R. XVILSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,207,488 Venable Deo. 5, 1916 1,790,696 Bridge Feb. 3, 1931 2,154,604 Perry Mar. 28, 1939 2,288,561 Webber June 30, 1942 2,292,680 Webber Aug. 11, 1942 2,331,542 Edelmann Oct. l2, 1943 2,345,921 Edelmann Apr. 4, 1944 2,368,123 Edelmann Jan. 30, 1945 2,394,835 Arant Feb. 12, 1946 

